1// SPDX-License-Identifier: BSD-3-Clause
2/*
3 * Copyright (c) 2020, MIPI Alliance, Inc.
4 *
5 * Author: Nicolas Pitre <npitre@baylibre.com>
6 *
7 * Core driver code with main interface to the I3C subsystem.
8 */
9
10#include <linux/bitfield.h>
11#include <linux/device.h>
12#include <linux/errno.h>
13#include <linux/i3c/master.h>
14#include <linux/interrupt.h>
15#include <linux/io.h>
16#include <linux/iopoll.h>
17#include <linux/module.h>
18#include <linux/platform_device.h>
19
20#include "hci.h"
21#include "ext_caps.h"
22#include "cmd.h"
23#include "dat.h"
24
25
26/*
27 * Host Controller Capabilities and Operation Registers
28 */
29
30#define reg_read(r)		readl(hci->base_regs + (r))
31#define reg_write(r, v)		writel(v, hci->base_regs + (r))
32#define reg_set(r, v)		reg_write(r, reg_read(r) | (v))
33#define reg_clear(r, v)		reg_write(r, reg_read(r) & ~(v))
34
35#define HCI_VERSION			0x00	/* HCI Version (in BCD) */
36
37#define HC_CONTROL			0x04
38#define HC_CONTROL_BUS_ENABLE		BIT(31)
39#define HC_CONTROL_RESUME		BIT(30)
40#define HC_CONTROL_ABORT		BIT(29)
41#define HC_CONTROL_HALT_ON_CMD_TIMEOUT	BIT(12)
42#define HC_CONTROL_HOT_JOIN_CTRL	BIT(8)	/* Hot-Join ACK/NACK Control */
43#define HC_CONTROL_I2C_TARGET_PRESENT	BIT(7)
44#define HC_CONTROL_PIO_MODE		BIT(6)	/* DMA/PIO Mode Selector */
45#define HC_CONTROL_DATA_BIG_ENDIAN	BIT(4)
46#define HC_CONTROL_IBA_INCLUDE		BIT(0)	/* Include I3C Broadcast Address */
47
48#define MASTER_DEVICE_ADDR		0x08	/* Master Device Address */
49#define MASTER_DYNAMIC_ADDR_VALID	BIT(31)	/* Dynamic Address is Valid */
50#define MASTER_DYNAMIC_ADDR(v)		FIELD_PREP(GENMASK(22, 16), v)
51
52#define HC_CAPABILITIES			0x0c
53#define HC_CAP_SG_DC_EN			BIT(30)
54#define HC_CAP_SG_IBI_EN		BIT(29)
55#define HC_CAP_SG_CR_EN			BIT(28)
56#define HC_CAP_MAX_DATA_LENGTH		GENMASK(24, 22)
57#define HC_CAP_CMD_SIZE			GENMASK(21, 20)
58#define HC_CAP_DIRECT_COMMANDS_EN	BIT(18)
59#define HC_CAP_MULTI_LANE_EN		BIT(15)
60#define HC_CAP_CMD_CCC_DEFBYTE		BIT(10)
61#define HC_CAP_HDR_BT_EN		BIT(8)
62#define HC_CAP_HDR_TS_EN		BIT(7)
63#define HC_CAP_HDR_DDR_EN		BIT(6)
64#define HC_CAP_NON_CURRENT_MASTER_CAP	BIT(5)	/* master handoff capable */
65#define HC_CAP_DATA_BYTE_CFG_EN		BIT(4)	/* endian selection possible */
66#define HC_CAP_AUTO_COMMAND		BIT(3)
67#define HC_CAP_COMBO_COMMAND		BIT(2)
68
69#define RESET_CONTROL			0x10
70#define BUS_RESET			BIT(31)
71#define BUS_RESET_TYPE			GENMASK(30, 29)
72#define IBI_QUEUE_RST			BIT(5)
73#define RX_FIFO_RST			BIT(4)
74#define TX_FIFO_RST			BIT(3)
75#define RESP_QUEUE_RST			BIT(2)
76#define CMD_QUEUE_RST			BIT(1)
77#define SOFT_RST			BIT(0)	/* Core Reset */
78
79#define PRESENT_STATE			0x14
80#define STATE_CURRENT_MASTER		BIT(2)
81
82#define INTR_STATUS			0x20
83#define INTR_STATUS_ENABLE		0x24
84#define INTR_SIGNAL_ENABLE		0x28
85#define INTR_FORCE			0x2c
86#define INTR_HC_CMD_SEQ_UFLOW_STAT	BIT(12)	/* Cmd Sequence Underflow */
87#define INTR_HC_RESET_CANCEL		BIT(11)	/* HC Cancelled Reset */
88#define INTR_HC_INTERNAL_ERR		BIT(10)	/* HC Internal Error */
89#define INTR_HC_PIO			BIT(8)	/* cascaded PIO interrupt */
90#define INTR_HC_RINGS			GENMASK(7, 0)
91
92#define DAT_SECTION			0x30	/* Device Address Table */
93#define DAT_ENTRY_SIZE			GENMASK(31, 28)
94#define DAT_TABLE_SIZE			GENMASK(18, 12)
95#define DAT_TABLE_OFFSET		GENMASK(11, 0)
96
97#define DCT_SECTION			0x34	/* Device Characteristics Table */
98#define DCT_ENTRY_SIZE			GENMASK(31, 28)
99#define DCT_TABLE_INDEX			GENMASK(23, 19)
100#define DCT_TABLE_SIZE			GENMASK(18, 12)
101#define DCT_TABLE_OFFSET		GENMASK(11, 0)
102
103#define RING_HEADERS_SECTION		0x38
104#define RING_HEADERS_OFFSET		GENMASK(15, 0)
105
106#define PIO_SECTION			0x3c
107#define PIO_REGS_OFFSET			GENMASK(15, 0)	/* PIO Offset */
108
109#define EXT_CAPS_SECTION		0x40
110#define EXT_CAPS_OFFSET			GENMASK(15, 0)
111
112#define IBI_NOTIFY_CTRL			0x58	/* IBI Notify Control */
113#define IBI_NOTIFY_SIR_REJECTED		BIT(3)	/* Rejected Target Interrupt Request */
114#define IBI_NOTIFY_MR_REJECTED		BIT(1)	/* Rejected Master Request Control */
115#define IBI_NOTIFY_HJ_REJECTED		BIT(0)	/* Rejected Hot-Join Control */
116
117#define DEV_CTX_BASE_LO			0x60
118#define DEV_CTX_BASE_HI			0x64
119
120
121static inline struct i3c_hci *to_i3c_hci(struct i3c_master_controller *m)
122{
123	return container_of(m, struct i3c_hci, master);
124}
125
126static int i3c_hci_bus_init(struct i3c_master_controller *m)
127{
128	struct i3c_hci *hci = to_i3c_hci(m);
129	struct i3c_device_info info;
130	int ret;
131
132	DBG("");
133
134	if (hci->cmd == &mipi_i3c_hci_cmd_v1) {
135		ret = mipi_i3c_hci_dat_v1.init(hci);
136		if (ret)
137			return ret;
138	}
139
140	ret = i3c_master_get_free_addr(m, 0);
141	if (ret < 0)
142		return ret;
143	reg_write(MASTER_DEVICE_ADDR,
144		  MASTER_DYNAMIC_ADDR(ret) | MASTER_DYNAMIC_ADDR_VALID);
145	memset(&info, 0, sizeof(info));
146	info.dyn_addr = ret;
147	ret = i3c_master_set_info(m, &info);
148	if (ret)
149		return ret;
150
151	ret = hci->io->init(hci);
152	if (ret)
153		return ret;
154
155	reg_set(HC_CONTROL, HC_CONTROL_BUS_ENABLE);
156	DBG("HC_CONTROL = %#x", reg_read(HC_CONTROL));
157
158	return 0;
159}
160
161static void i3c_hci_bus_cleanup(struct i3c_master_controller *m)
162{
163	struct i3c_hci *hci = to_i3c_hci(m);
164	struct platform_device *pdev = to_platform_device(m->dev.parent);
165
166	DBG("");
167
168	reg_clear(HC_CONTROL, HC_CONTROL_BUS_ENABLE);
169	synchronize_irq(platform_get_irq(pdev, 0));
170	hci->io->cleanup(hci);
171	if (hci->cmd == &mipi_i3c_hci_cmd_v1)
172		mipi_i3c_hci_dat_v1.cleanup(hci);
173}
174
175void mipi_i3c_hci_resume(struct i3c_hci *hci)
176{
177	reg_set(HC_CONTROL, HC_CONTROL_RESUME);
178}
179
180/* located here rather than pio.c because needed bits are in core reg space */
181void mipi_i3c_hci_pio_reset(struct i3c_hci *hci)
182{
183	reg_write(RESET_CONTROL, RX_FIFO_RST | TX_FIFO_RST | RESP_QUEUE_RST);
184}
185
186/* located here rather than dct.c because needed bits are in core reg space */
187void mipi_i3c_hci_dct_index_reset(struct i3c_hci *hci)
188{
189	reg_write(DCT_SECTION, FIELD_PREP(DCT_TABLE_INDEX, 0));
190}
191
192static int i3c_hci_send_ccc_cmd(struct i3c_master_controller *m,
193				struct i3c_ccc_cmd *ccc)
194{
195	struct i3c_hci *hci = to_i3c_hci(m);
196	struct hci_xfer *xfer;
197	bool raw = !!(hci->quirks & HCI_QUIRK_RAW_CCC);
198	bool prefixed = raw && !!(ccc->id & I3C_CCC_DIRECT);
199	unsigned int nxfers = ccc->ndests + prefixed;
200	DECLARE_COMPLETION_ONSTACK(done);
201	int i, last, ret = 0;
202
203	DBG("cmd=%#x rnw=%d ndests=%d data[0].len=%d",
204	    ccc->id, ccc->rnw, ccc->ndests, ccc->dests[0].payload.len);
205
206	xfer = hci_alloc_xfer(nxfers);
207	if (!xfer)
208		return -ENOMEM;
209
210	if (prefixed) {
211		xfer->data = NULL;
212		xfer->data_len = 0;
213		xfer->rnw = false;
214		hci->cmd->prep_ccc(hci, xfer, I3C_BROADCAST_ADDR,
215				   ccc->id, true);
216		xfer++;
217	}
218
219	for (i = 0; i < nxfers - prefixed; i++) {
220		xfer[i].data = ccc->dests[i].payload.data;
221		xfer[i].data_len = ccc->dests[i].payload.len;
222		xfer[i].rnw = ccc->rnw;
223		ret = hci->cmd->prep_ccc(hci, &xfer[i], ccc->dests[i].addr,
224					 ccc->id, raw);
225		if (ret)
226			goto out;
227		xfer[i].cmd_desc[0] |= CMD_0_ROC;
228	}
229	last = i - 1;
230	xfer[last].cmd_desc[0] |= CMD_0_TOC;
231	xfer[last].completion = &done;
232
233	if (prefixed)
234		xfer--;
235
236	ret = hci->io->queue_xfer(hci, xfer, nxfers);
237	if (ret)
238		goto out;
239	if (!wait_for_completion_timeout(&done, HZ) &&
240	    hci->io->dequeue_xfer(hci, xfer, nxfers)) {
241		ret = -ETIME;
242		goto out;
243	}
244	for (i = prefixed; i < nxfers; i++) {
245		if (ccc->rnw)
246			ccc->dests[i - prefixed].payload.len =
247				RESP_DATA_LENGTH(xfer[i].response);
248		switch (RESP_STATUS(xfer[i].response)) {
249		case RESP_SUCCESS:
250			continue;
251		case RESP_ERR_ADDR_HEADER:
252		case RESP_ERR_NACK:
253			ccc->err = I3C_ERROR_M2;
254			fallthrough;
255		default:
256			ret = -EIO;
257			goto out;
258		}
259	}
260
261	if (ccc->rnw)
262		DBG("got: %*ph",
263		    ccc->dests[0].payload.len, ccc->dests[0].payload.data);
264
265out:
266	hci_free_xfer(xfer, nxfers);
267	return ret;
268}
269
270static int i3c_hci_daa(struct i3c_master_controller *m)
271{
272	struct i3c_hci *hci = to_i3c_hci(m);
273
274	DBG("");
275
276	return hci->cmd->perform_daa(hci);
277}
278
279static int i3c_hci_alloc_safe_xfer_buf(struct i3c_hci *hci,
280				       struct hci_xfer *xfer)
281{
282	if (hci->io != &mipi_i3c_hci_dma ||
283	    xfer->data == NULL || !is_vmalloc_addr(xfer->data))
284		return 0;
285
286	if (xfer->rnw)
287		xfer->bounce_buf = kzalloc(xfer->data_len, GFP_KERNEL);
288	else
289		xfer->bounce_buf = kmemdup(xfer->data,
290					   xfer->data_len, GFP_KERNEL);
291
292	return xfer->bounce_buf == NULL ? -ENOMEM : 0;
293}
294
295static void i3c_hci_free_safe_xfer_buf(struct i3c_hci *hci,
296				       struct hci_xfer *xfer)
297{
298	if (hci->io != &mipi_i3c_hci_dma || xfer->bounce_buf == NULL)
299		return;
300
301	if (xfer->rnw)
302		memcpy(xfer->data, xfer->bounce_buf, xfer->data_len);
303
304	kfree(xfer->bounce_buf);
305}
306
307static int i3c_hci_priv_xfers(struct i3c_dev_desc *dev,
308			      struct i3c_priv_xfer *i3c_xfers,
309			      int nxfers)
310{
311	struct i3c_master_controller *m = i3c_dev_get_master(dev);
312	struct i3c_hci *hci = to_i3c_hci(m);
313	struct hci_xfer *xfer;
314	DECLARE_COMPLETION_ONSTACK(done);
315	unsigned int size_limit;
316	int i, last, ret = 0;
317
318	DBG("nxfers = %d", nxfers);
319
320	xfer = hci_alloc_xfer(nxfers);
321	if (!xfer)
322		return -ENOMEM;
323
324	size_limit = 1U << (16 + FIELD_GET(HC_CAP_MAX_DATA_LENGTH, hci->caps));
325
326	for (i = 0; i < nxfers; i++) {
327		xfer[i].data_len = i3c_xfers[i].len;
328		ret = -EFBIG;
329		if (xfer[i].data_len >= size_limit)
330			goto out;
331		xfer[i].rnw = i3c_xfers[i].rnw;
332		if (i3c_xfers[i].rnw) {
333			xfer[i].data = i3c_xfers[i].data.in;
334		} else {
335			/* silence the const qualifier warning with a cast */
336			xfer[i].data = (void *) i3c_xfers[i].data.out;
337		}
338		hci->cmd->prep_i3c_xfer(hci, dev, &xfer[i]);
339		xfer[i].cmd_desc[0] |= CMD_0_ROC;
340		ret = i3c_hci_alloc_safe_xfer_buf(hci, &xfer[i]);
341		if (ret)
342			goto out;
343	}
344	last = i - 1;
345	xfer[last].cmd_desc[0] |= CMD_0_TOC;
346	xfer[last].completion = &done;
347
348	ret = hci->io->queue_xfer(hci, xfer, nxfers);
349	if (ret)
350		goto out;
351	if (!wait_for_completion_timeout(&done, HZ) &&
352	    hci->io->dequeue_xfer(hci, xfer, nxfers)) {
353		ret = -ETIME;
354		goto out;
355	}
356	for (i = 0; i < nxfers; i++) {
357		if (i3c_xfers[i].rnw)
358			i3c_xfers[i].len = RESP_DATA_LENGTH(xfer[i].response);
359		if (RESP_STATUS(xfer[i].response) != RESP_SUCCESS) {
360			ret = -EIO;
361			goto out;
362		}
363	}
364
365out:
366	for (i = 0; i < nxfers; i++)
367		i3c_hci_free_safe_xfer_buf(hci, &xfer[i]);
368
369	hci_free_xfer(xfer, nxfers);
370	return ret;
371}
372
373static int i3c_hci_i2c_xfers(struct i2c_dev_desc *dev,
374			     const struct i2c_msg *i2c_xfers, int nxfers)
375{
376	struct i3c_master_controller *m = i2c_dev_get_master(dev);
377	struct i3c_hci *hci = to_i3c_hci(m);
378	struct hci_xfer *xfer;
379	DECLARE_COMPLETION_ONSTACK(done);
380	int i, last, ret = 0;
381
382	DBG("nxfers = %d", nxfers);
383
384	xfer = hci_alloc_xfer(nxfers);
385	if (!xfer)
386		return -ENOMEM;
387
388	for (i = 0; i < nxfers; i++) {
389		xfer[i].data = i2c_xfers[i].buf;
390		xfer[i].data_len = i2c_xfers[i].len;
391		xfer[i].rnw = i2c_xfers[i].flags & I2C_M_RD;
392		hci->cmd->prep_i2c_xfer(hci, dev, &xfer[i]);
393		xfer[i].cmd_desc[0] |= CMD_0_ROC;
394		ret = i3c_hci_alloc_safe_xfer_buf(hci, &xfer[i]);
395		if (ret)
396			goto out;
397	}
398	last = i - 1;
399	xfer[last].cmd_desc[0] |= CMD_0_TOC;
400	xfer[last].completion = &done;
401
402	ret = hci->io->queue_xfer(hci, xfer, nxfers);
403	if (ret)
404		goto out;
405	if (!wait_for_completion_timeout(&done, HZ) &&
406	    hci->io->dequeue_xfer(hci, xfer, nxfers)) {
407		ret = -ETIME;
408		goto out;
409	}
410	for (i = 0; i < nxfers; i++) {
411		if (RESP_STATUS(xfer[i].response) != RESP_SUCCESS) {
412			ret = -EIO;
413			goto out;
414		}
415	}
416
417out:
418	for (i = 0; i < nxfers; i++)
419		i3c_hci_free_safe_xfer_buf(hci, &xfer[i]);
420
421	hci_free_xfer(xfer, nxfers);
422	return ret;
423}
424
425static int i3c_hci_attach_i3c_dev(struct i3c_dev_desc *dev)
426{
427	struct i3c_master_controller *m = i3c_dev_get_master(dev);
428	struct i3c_hci *hci = to_i3c_hci(m);
429	struct i3c_hci_dev_data *dev_data;
430	int ret;
431
432	DBG("");
433
434	dev_data = kzalloc(sizeof(*dev_data), GFP_KERNEL);
435	if (!dev_data)
436		return -ENOMEM;
437	if (hci->cmd == &mipi_i3c_hci_cmd_v1) {
438		ret = mipi_i3c_hci_dat_v1.alloc_entry(hci);
439		if (ret < 0) {
440			kfree(dev_data);
441			return ret;
442		}
443		mipi_i3c_hci_dat_v1.set_dynamic_addr(hci, ret, dev->info.dyn_addr);
444		dev_data->dat_idx = ret;
445	}
446	i3c_dev_set_master_data(dev, dev_data);
447	return 0;
448}
449
450static int i3c_hci_reattach_i3c_dev(struct i3c_dev_desc *dev, u8 old_dyn_addr)
451{
452	struct i3c_master_controller *m = i3c_dev_get_master(dev);
453	struct i3c_hci *hci = to_i3c_hci(m);
454	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
455
456	DBG("");
457
458	if (hci->cmd == &mipi_i3c_hci_cmd_v1)
459		mipi_i3c_hci_dat_v1.set_dynamic_addr(hci, dev_data->dat_idx,
460					     dev->info.dyn_addr);
461	return 0;
462}
463
464static void i3c_hci_detach_i3c_dev(struct i3c_dev_desc *dev)
465{
466	struct i3c_master_controller *m = i3c_dev_get_master(dev);
467	struct i3c_hci *hci = to_i3c_hci(m);
468	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
469
470	DBG("");
471
472	i3c_dev_set_master_data(dev, NULL);
473	if (hci->cmd == &mipi_i3c_hci_cmd_v1)
474		mipi_i3c_hci_dat_v1.free_entry(hci, dev_data->dat_idx);
475	kfree(dev_data);
476}
477
478static int i3c_hci_attach_i2c_dev(struct i2c_dev_desc *dev)
479{
480	struct i3c_master_controller *m = i2c_dev_get_master(dev);
481	struct i3c_hci *hci = to_i3c_hci(m);
482	struct i3c_hci_dev_data *dev_data;
483	int ret;
484
485	DBG("");
486
487	if (hci->cmd != &mipi_i3c_hci_cmd_v1)
488		return 0;
489	dev_data = kzalloc(sizeof(*dev_data), GFP_KERNEL);
490	if (!dev_data)
491		return -ENOMEM;
492	ret = mipi_i3c_hci_dat_v1.alloc_entry(hci);
493	if (ret < 0) {
494		kfree(dev_data);
495		return ret;
496	}
497	mipi_i3c_hci_dat_v1.set_static_addr(hci, ret, dev->addr);
498	mipi_i3c_hci_dat_v1.set_flags(hci, ret, DAT_0_I2C_DEVICE, 0);
499	dev_data->dat_idx = ret;
500	i2c_dev_set_master_data(dev, dev_data);
501	return 0;
502}
503
504static void i3c_hci_detach_i2c_dev(struct i2c_dev_desc *dev)
505{
506	struct i3c_master_controller *m = i2c_dev_get_master(dev);
507	struct i3c_hci *hci = to_i3c_hci(m);
508	struct i3c_hci_dev_data *dev_data = i2c_dev_get_master_data(dev);
509
510	DBG("");
511
512	if (dev_data) {
513		i2c_dev_set_master_data(dev, NULL);
514		if (hci->cmd == &mipi_i3c_hci_cmd_v1)
515			mipi_i3c_hci_dat_v1.free_entry(hci, dev_data->dat_idx);
516		kfree(dev_data);
517	}
518}
519
520static int i3c_hci_request_ibi(struct i3c_dev_desc *dev,
521			       const struct i3c_ibi_setup *req)
522{
523	struct i3c_master_controller *m = i3c_dev_get_master(dev);
524	struct i3c_hci *hci = to_i3c_hci(m);
525	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
526	unsigned int dat_idx = dev_data->dat_idx;
527
528	if (req->max_payload_len != 0)
529		mipi_i3c_hci_dat_v1.set_flags(hci, dat_idx, DAT_0_IBI_PAYLOAD, 0);
530	else
531		mipi_i3c_hci_dat_v1.clear_flags(hci, dat_idx, DAT_0_IBI_PAYLOAD, 0);
532	return hci->io->request_ibi(hci, dev, req);
533}
534
535static void i3c_hci_free_ibi(struct i3c_dev_desc *dev)
536{
537	struct i3c_master_controller *m = i3c_dev_get_master(dev);
538	struct i3c_hci *hci = to_i3c_hci(m);
539
540	hci->io->free_ibi(hci, dev);
541}
542
543static int i3c_hci_enable_ibi(struct i3c_dev_desc *dev)
544{
545	struct i3c_master_controller *m = i3c_dev_get_master(dev);
546	struct i3c_hci *hci = to_i3c_hci(m);
547	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
548
549	mipi_i3c_hci_dat_v1.clear_flags(hci, dev_data->dat_idx, DAT_0_SIR_REJECT, 0);
550	return i3c_master_enec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
551}
552
553static int i3c_hci_disable_ibi(struct i3c_dev_desc *dev)
554{
555	struct i3c_master_controller *m = i3c_dev_get_master(dev);
556	struct i3c_hci *hci = to_i3c_hci(m);
557	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
558
559	mipi_i3c_hci_dat_v1.set_flags(hci, dev_data->dat_idx, DAT_0_SIR_REJECT, 0);
560	return i3c_master_disec_locked(m, dev->info.dyn_addr, I3C_CCC_EVENT_SIR);
561}
562
563static void i3c_hci_recycle_ibi_slot(struct i3c_dev_desc *dev,
564				     struct i3c_ibi_slot *slot)
565{
566	struct i3c_master_controller *m = i3c_dev_get_master(dev);
567	struct i3c_hci *hci = to_i3c_hci(m);
568
569	hci->io->recycle_ibi_slot(hci, dev, slot);
570}
571
572static const struct i3c_master_controller_ops i3c_hci_ops = {
573	.bus_init		= i3c_hci_bus_init,
574	.bus_cleanup		= i3c_hci_bus_cleanup,
575	.do_daa			= i3c_hci_daa,
576	.send_ccc_cmd		= i3c_hci_send_ccc_cmd,
577	.priv_xfers		= i3c_hci_priv_xfers,
578	.i2c_xfers		= i3c_hci_i2c_xfers,
579	.attach_i3c_dev		= i3c_hci_attach_i3c_dev,
580	.reattach_i3c_dev	= i3c_hci_reattach_i3c_dev,
581	.detach_i3c_dev		= i3c_hci_detach_i3c_dev,
582	.attach_i2c_dev		= i3c_hci_attach_i2c_dev,
583	.detach_i2c_dev		= i3c_hci_detach_i2c_dev,
584	.request_ibi		= i3c_hci_request_ibi,
585	.free_ibi		= i3c_hci_free_ibi,
586	.enable_ibi		= i3c_hci_enable_ibi,
587	.disable_ibi		= i3c_hci_disable_ibi,
588	.recycle_ibi_slot	= i3c_hci_recycle_ibi_slot,
589};
590
591static irqreturn_t i3c_hci_irq_handler(int irq, void *dev_id)
592{
593	struct i3c_hci *hci = dev_id;
594	irqreturn_t result = IRQ_NONE;
595	u32 val;
596
597	val = reg_read(INTR_STATUS);
598	DBG("INTR_STATUS = %#x", val);
599
600	if (val) {
601		reg_write(INTR_STATUS, val);
602	} else {
603		/* v1.0 does not have PIO cascaded notification bits */
604		val |= INTR_HC_PIO;
605	}
606
607	if (val & INTR_HC_RESET_CANCEL) {
608		DBG("cancelled reset");
609		val &= ~INTR_HC_RESET_CANCEL;
610	}
611	if (val & INTR_HC_INTERNAL_ERR) {
612		dev_err(&hci->master.dev, "Host Controller Internal Error\n");
613		val &= ~INTR_HC_INTERNAL_ERR;
614	}
615	if (val & INTR_HC_PIO) {
616		hci->io->irq_handler(hci, 0);
617		val &= ~INTR_HC_PIO;
618	}
619	if (val & INTR_HC_RINGS) {
620		hci->io->irq_handler(hci, val & INTR_HC_RINGS);
621		val &= ~INTR_HC_RINGS;
622	}
623	if (val)
624		dev_err(&hci->master.dev, "unexpected INTR_STATUS %#x\n", val);
625	else
626		result = IRQ_HANDLED;
627
628	return result;
629}
630
631static int i3c_hci_init(struct i3c_hci *hci)
632{
633	u32 regval, offset;
634	int ret;
635
636	/* Validate HCI hardware version */
637	regval = reg_read(HCI_VERSION);
638	hci->version_major = (regval >> 8) & 0xf;
639	hci->version_minor = (regval >> 4) & 0xf;
640	hci->revision = regval & 0xf;
641	dev_notice(&hci->master.dev, "MIPI I3C HCI v%u.%u r%02u\n",
642		   hci->version_major, hci->version_minor, hci->revision);
643	/* known versions */
644	switch (regval & ~0xf) {
645	case 0x100:	/* version 1.0 */
646	case 0x110:	/* version 1.1 */
647	case 0x200:	/* version 2.0 */
648		break;
649	default:
650		dev_err(&hci->master.dev, "unsupported HCI version\n");
651		return -EPROTONOSUPPORT;
652	}
653
654	hci->caps = reg_read(HC_CAPABILITIES);
655	DBG("caps = %#x", hci->caps);
656
657	regval = reg_read(DAT_SECTION);
658	offset = FIELD_GET(DAT_TABLE_OFFSET, regval);
659	hci->DAT_regs = offset ? hci->base_regs + offset : NULL;
660	hci->DAT_entries = FIELD_GET(DAT_TABLE_SIZE, regval);
661	hci->DAT_entry_size = FIELD_GET(DAT_ENTRY_SIZE, regval) ? 0 : 8;
662	dev_info(&hci->master.dev, "DAT: %u %u-bytes entries at offset %#x\n",
663		 hci->DAT_entries, hci->DAT_entry_size, offset);
664
665	regval = reg_read(DCT_SECTION);
666	offset = FIELD_GET(DCT_TABLE_OFFSET, regval);
667	hci->DCT_regs = offset ? hci->base_regs + offset : NULL;
668	hci->DCT_entries = FIELD_GET(DCT_TABLE_SIZE, regval);
669	hci->DCT_entry_size = FIELD_GET(DCT_ENTRY_SIZE, regval) ? 0 : 16;
670	dev_info(&hci->master.dev, "DCT: %u %u-bytes entries at offset %#x\n",
671		 hci->DCT_entries, hci->DCT_entry_size, offset);
672
673	regval = reg_read(RING_HEADERS_SECTION);
674	offset = FIELD_GET(RING_HEADERS_OFFSET, regval);
675	hci->RHS_regs = offset ? hci->base_regs + offset : NULL;
676	dev_info(&hci->master.dev, "Ring Headers at offset %#x\n", offset);
677
678	regval = reg_read(PIO_SECTION);
679	offset = FIELD_GET(PIO_REGS_OFFSET, regval);
680	hci->PIO_regs = offset ? hci->base_regs + offset : NULL;
681	dev_info(&hci->master.dev, "PIO section at offset %#x\n", offset);
682
683	regval = reg_read(EXT_CAPS_SECTION);
684	offset = FIELD_GET(EXT_CAPS_OFFSET, regval);
685	hci->EXTCAPS_regs = offset ? hci->base_regs + offset : NULL;
686	dev_info(&hci->master.dev, "Extended Caps at offset %#x\n", offset);
687
688	ret = i3c_hci_parse_ext_caps(hci);
689	if (ret)
690		return ret;
691
692	/*
693	 * Now let's reset the hardware.
694	 * SOFT_RST must be clear before we write to it.
695	 * Then we must wait until it clears again.
696	 */
697	ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
698				 !(regval & SOFT_RST), 1, 10000);
699	if (ret)
700		return -ENXIO;
701	reg_write(RESET_CONTROL, SOFT_RST);
702	ret = readx_poll_timeout(reg_read, RESET_CONTROL, regval,
703				 !(regval & SOFT_RST), 1, 10000);
704	if (ret)
705		return -ENXIO;
706
707	/* Disable all interrupts and allow all signal updates */
708	reg_write(INTR_SIGNAL_ENABLE, 0x0);
709	reg_write(INTR_STATUS_ENABLE, 0xffffffff);
710
711	/* Make sure our data ordering fits the host's */
712	regval = reg_read(HC_CONTROL);
713	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
714		if (!(regval & HC_CONTROL_DATA_BIG_ENDIAN)) {
715			regval |= HC_CONTROL_DATA_BIG_ENDIAN;
716			reg_write(HC_CONTROL, regval);
717			regval = reg_read(HC_CONTROL);
718			if (!(regval & HC_CONTROL_DATA_BIG_ENDIAN)) {
719				dev_err(&hci->master.dev, "cannot set BE mode\n");
720				return -EOPNOTSUPP;
721			}
722		}
723	} else {
724		if (regval & HC_CONTROL_DATA_BIG_ENDIAN) {
725			regval &= ~HC_CONTROL_DATA_BIG_ENDIAN;
726			reg_write(HC_CONTROL, regval);
727			regval = reg_read(HC_CONTROL);
728			if (regval & HC_CONTROL_DATA_BIG_ENDIAN) {
729				dev_err(&hci->master.dev, "cannot clear BE mode\n");
730				return -EOPNOTSUPP;
731			}
732		}
733	}
734
735	/* Select our command descriptor model */
736	switch (FIELD_GET(HC_CAP_CMD_SIZE, hci->caps)) {
737	case 0:
738		hci->cmd = &mipi_i3c_hci_cmd_v1;
739		break;
740	case 1:
741		hci->cmd = &mipi_i3c_hci_cmd_v2;
742		break;
743	default:
744		dev_err(&hci->master.dev, "wrong CMD_SIZE capability value\n");
745		return -EINVAL;
746	}
747
748	/* Try activating DMA operations first */
749	if (hci->RHS_regs) {
750		reg_clear(HC_CONTROL, HC_CONTROL_PIO_MODE);
751		if (reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE) {
752			dev_err(&hci->master.dev, "PIO mode is stuck\n");
753			ret = -EIO;
754		} else {
755			hci->io = &mipi_i3c_hci_dma;
756			dev_info(&hci->master.dev, "Using DMA\n");
757		}
758	}
759
760	/* If no DMA, try PIO */
761	if (!hci->io && hci->PIO_regs) {
762		reg_set(HC_CONTROL, HC_CONTROL_PIO_MODE);
763		if (!(reg_read(HC_CONTROL) & HC_CONTROL_PIO_MODE)) {
764			dev_err(&hci->master.dev, "DMA mode is stuck\n");
765			ret = -EIO;
766		} else {
767			hci->io = &mipi_i3c_hci_pio;
768			dev_info(&hci->master.dev, "Using PIO\n");
769		}
770	}
771
772	if (!hci->io) {
773		dev_err(&hci->master.dev, "neither DMA nor PIO can be used\n");
774		if (!ret)
775			ret = -EINVAL;
776		return ret;
777	}
778
779	return 0;
780}
781
782static int i3c_hci_probe(struct platform_device *pdev)
783{
784	struct i3c_hci *hci;
785	int irq, ret;
786
787	hci = devm_kzalloc(&pdev->dev, sizeof(*hci), GFP_KERNEL);
788	if (!hci)
789		return -ENOMEM;
790	hci->base_regs = devm_platform_ioremap_resource(pdev, 0);
791	if (IS_ERR(hci->base_regs))
792		return PTR_ERR(hci->base_regs);
793
794	platform_set_drvdata(pdev, hci);
795	/* temporary for dev_printk's, to be replaced in i3c_master_register */
796	hci->master.dev.init_name = dev_name(&pdev->dev);
797
798	ret = i3c_hci_init(hci);
799	if (ret)
800		return ret;
801
802	irq = platform_get_irq(pdev, 0);
803	ret = devm_request_irq(&pdev->dev, irq, i3c_hci_irq_handler,
804			       0, NULL, hci);
805	if (ret)
806		return ret;
807
808	ret = i3c_master_register(&hci->master, &pdev->dev,
809				  &i3c_hci_ops, false);
810	if (ret)
811		return ret;
812
813	return 0;
814}
815
816static void i3c_hci_remove(struct platform_device *pdev)
817{
818	struct i3c_hci *hci = platform_get_drvdata(pdev);
819
820	i3c_master_unregister(&hci->master);
821}
822
823static const __maybe_unused struct of_device_id i3c_hci_of_match[] = {
824	{ .compatible = "mipi-i3c-hci", },
825	{},
826};
827MODULE_DEVICE_TABLE(of, i3c_hci_of_match);
828
829static struct platform_driver i3c_hci_driver = {
830	.probe = i3c_hci_probe,
831	.remove_new = i3c_hci_remove,
832	.driver = {
833		.name = "mipi-i3c-hci",
834		.of_match_table = of_match_ptr(i3c_hci_of_match),
835	},
836};
837module_platform_driver(i3c_hci_driver);
838MODULE_ALIAS("platform:mipi-i3c-hci");
839
840MODULE_AUTHOR("Nicolas Pitre <npitre@baylibre.com>");
841MODULE_DESCRIPTION("MIPI I3C HCI driver");
842MODULE_LICENSE("Dual BSD/GPL");
843